1. Field of the Invention
The present invention relates to an engine operated machine, and more particular to an engine operated machine in which an electric motor that is also operated as a power generator is connected to an output shaft of an engine.
2. Description of the Related Art
An agricultural working machine, called as a hybrid powered engine operated machine structured such that both an engine power and an electric motor power can be used has been known. For example, in Japanese Patent Application Laid-Open No. 2001-161114, there is proposed an engine drive passenger farming machine in which in the case that a load of the farming machine is small, a surplus energy that is generated by an engine driven generator is accumulated, and in the case that the load is large, an electric motor is driven by the electric power. In the passenger farming machine, it is judged that the load is large, in the case that an exhaust temperature of the engine becomes equal to or more than a predetermined value.
In the passenger farming machine described in the publication mentioned above, the electric motor output is combined with the engine output, whereby a large driving force can be obtained. However, since it is judged based on the exhaust temperature that the large driving force is actually required, it is hard to execute such an operation as to supplement only a necessary driving force in correspondence to a rapid load change.